How does the UH-60 manage rotor RPM during engine power changes and what is the role of the rotor speed governor?

How does the UH-60 manage rotor RPM during engine power changes and what is the role of the rotor speed governor?

• A. The governor modulates cyclic to keep rotor rpm within limits.
• B. The governor modulates collective to keep rotor rpm within limits; engine power changes are compensated automatically to maintain rpm.
• C. The governor directly controls engine RPM.
• D. Rotor RPM is fixed and not affected by engine power changes.

Answer: (B)

The system keeps rotor speed within a narrow range by using a rotor speed governor that automatically adjusts the collective pitch. When engine power changes, the rotor tends to speed up or slow down. The governor monitors rotor RPM and, if it detects a deviation from the set value, it changes collective pitch to balance the rotor load with the available power. If power rises and RPM tends to climb, the governor lowers collective to reduce blade lift and bring RPM back down. If power drops and RPM tends to fall, the governor increases collective to raise blade lift and bring RPM back up. This automatic adjustment means engine power changes are compensated without the pilot having to manually tweak RPM. The governor acts on the collective, not cyclic, and it doesn’t directly control engine RPM. Rotor RPM is not fixed and will vary with power, airload, and flight conditions, but is kept within limits by the governor.

The system keeps rotor speed within a narrow range by using a rotor speed governor that automatically adjusts the collective pitch. When engine power changes, the rotor tends to speed up or slow down. The governor monitors rotor RPM and, if it detects a deviation from the set value, it changes collective pitch to balance the rotor load with the available power. If power rises and RPM tends to climb, the governor lowers collective to reduce blade lift and bring RPM back down. If power drops and RPM tends to fall, the governor increases collective to raise blade lift and bring RPM back up. This automatic adjustment means engine power changes are compensated without the pilot having to manually tweak RPM. The governor acts on the collective, not cyclic, and it doesn’t directly control engine RPM. Rotor RPM is not fixed and will vary with power, airload, and flight conditions, but is kept within limits by the governor.